Successful term delivery of spontaneous twin pregnancy in a woman with bicorporeal septate uterus: A case report.

Herein, we report the first case of successful term delivery of twins in a patient with bicorporeal septate uterus via natural conception. The patient had been diagnosed with complete septate, didelphys and bicornuate uterus during different phases of her three pregnancies. Based on follow-up data at six weeks and then six months post-partum of the last pregnancy, we found that the abnormalities presented in our case did not fit the criteria of any categories following American Fertility Society and European Society of Human Reproduction and Embryology-European Society for Gynaecological Endoscopy classification systems. After comprehensive review of the uterine morphologic characteristics, embryology and pregnancy outcome, we considered 'bicorporeal septate uterus' the most appropriate diagnosis. This case emphasized the atypical changes of uterine shape as twin pregnancy advances and its influence on productive performance and pregnancy outcome in uterine malformation. It also raised concern regarding the usability and comprehensiveness of the two most popular classification systems.